Math-how much will it come 2 with taxes?

Question

1-macbook for 1099

2-macbook for 1299

and

3-macbook for 1499

Answer 1

Multiply the price by the tax rate expressed as a decimal.  If the rate is 6.5%, multiply the price by .065

Answer 2

Price + (price x tax rate) = how much it will come to.  So the first macbook is 1099 plus (1099 x .0725 (for 7.25 % sales tax)) or $79.68 equals $1178.68

So you also need to know what the sales tax rate is for the area in which you are buying this item.